Extended data retention solutions export backup data from a primary backup data storage system and/or media to tape, or other lower cost but less readily-accessible media, for long term retention. The exported backup can, if needed, be imported from the tape or other media, for example sometime after the backup is no longer available on the primary backup media.
A user may desire to restore only part of a backup that is stored on tape or similar media. Performing a partial restore from tape or similar media presents certain challenges. For example, browsing and locating the desired data typically consumes time and may require the use of large amounts of storage to stage data as data from the backup is restored and the desired data is located. In addition, data required to perform the partial restore may be scattered on tape, which makes partial restores slow and can also lead to wear and tear of the tape media due to the “shoe shining” effect.
Another challenge in this context is to support partial restore with respect to multiple different applications. Application plugins provided to enable backup clients to be used with different applications may use different logic as required by the requirements of the particular application the data of which is to be backed up. What is partially restorable or desired to be partially restorable may be different for different plugins and can be defined only by the plugin for an application.